Effect of Silver Nanoparticles on White-Rot Wood Decay and Some Physical Properties of Three Tropical Wood Species

Wood is one of the most widely used materials and is used in many applications. However, decay resistance of wood is limited in tropical conditions. Nanotechnology applications have potential for improving materials. In this study, a solution with a concentration of 50 ppm silver nanoparticles was incorporated by pressure into three commercial species (Acacia mangium, Cedrela odorata, and Vochysia guatemalensis) of Costa Rica. The white-rot fungus (Trametes versicolor) was tested, and some physical properties were also measured. According to the results, synthetized silver nanoparticles (10-25 nm) presented little agglomeration and were adequately distributed. The retention achieved was 25-102 silver mg/kg-1 of wood, varying among species and with presence of sapwood and heartwood. Mass loss was less than 5% in wood treated with silver nanoparticles; thus, the wood was classified as highly resistant or class A. Meanwhile, untreated wood presented losses greater than 20% with white-rot fungi. Also, water absorption capacity decreased for wood treated with silver nanoparticles in the three species tested, and dimensional stability increased for Cedrela odorata and Vochysia guatemalensis treated with silver nanoparticles

The Apical Submembrane Cytoskeleton Participates in the Organization of the Apical Pole in Epithelial Cells

In a previous publication (Rodriguez, M.L., M. Brignoni, and P.J.I. Salas. 1994. J. Cell Sci. 107: 3145–3151), we described the existence of a terminal web-like structure in nonbrush border cells, which comprises a specifically apical cytokeratin, presumably cytokeratin 19. In the present study we confirmed the apical distribution of cytokeratin 19 and expanded that observation to other epithelial cells in tissue culture and in vivo. In tissue culture, subconfluent cell stocks under continuous treatment with two different 21-mer phosphorothioate oligodeoxy nucleotides that targeted cytokeratin 19 mRNA enabled us to obtain confluent monolayers with a partial (40–70%) and transitory reduction in this protein. The expression of other cytoskeletal proteins was undisturbed. This downregulation of cytokeratin 19 resulted in (a) decrease in the number of microvilli; (b) disorganization of the apical (but not lateral or basal) filamentous actin and abnormal apical microtubules; and (c) depletion or redistribution of apical membrane proteins as determined by differential apical–basolateral biotinylation. In fact, a subset of detergent-insoluble proteins was not expressed on the cell surface in cells with lower levels of cytokeratin 19. Apical proteins purified in the detergent phase of Triton X-114 (typically integral membrane proteins) and those differentially extracted in Triton X-100 at 37°C or in n-octyl-β-d-glycoside at 4°C (representative of GPIanchored proteins), appeared partially redistributed to the basolateral domain. A transmembrane apical protein, sucrase isomaltase, was found mispolarized in a subpopulation of the cells treated with antisense oligonucleotides, while the basolateral polarity of Na+– K+ATPase was not affected. Both sucrase isomaltase and alkaline phosphatase (a GPI-anchored protein) appeared partially depolarized in A19 treated CACO-2 monolayers as determined by differential biotinylation, affinity purification, and immunoblot. These results suggest that an apical submembrane cytoskeleton of intermediate filaments is expressed in a number of epithelia, including those without a brush border, although it may not be universal. In addition, these data indicate that this structure is involved in the organization of the apical region of the cytoplasm and the apical membrane

Aspectos tefrológicos de la erupción del volcán Quizapú de 1932 en la región de la laguna Llancanelo, Payenia (Mendoza, Argentina)

El Volcán Quizapú es parte del Complejo Volcánico Cerro Azul-Descabezado Grande, ubicado en la Provincia de Talca, Chile (36,67°S - 70,77°O, altura máxima: 3788 m s.n.m.). La erupción del 10 de abril de 1932 fue uno de los mayores eventos volcánicos del siglo XX. Tuvo un carácter pliniano y arrojó un volumen de tefras entre 5 y 30 km3 (según diferentes autores), que por efecto de los vientos dominantes del oeste cubrieron gran parte de la región central de Argentina, llegando a la costa atlántica y afectando a otros países del este de Sudamérica. Los efectos climáticos y el impacto en las regiones más proximales del sur de Mendoza, particularmente en el Departamento de Malargüe, fueron muy significativos. El estudio de los eyectos constituye un campo de exploración de gran valor no solamente para conocer las características, alcances y efectos de esa erupción sino también para evaluar aspectos relacionados con la tefrología. En esta contribución se analiza un depósito de tefras en los alrededores de la Laguna Llancanelo, en las cercanías de Malargüe, una de las áreas más afectadas por la erupción. Las determinaciones sedimentológicas, mineralógicas y texturales (petrografía, microscopía electrónica y determinaciones químicas semicuantitativas con EDS) permitieron caracterizar la composición granulométrica, petrográfica y química semicuantitativa de las tefras. Estas características son afines a las de los materiales piroclásticos eyectados por la erupción del volcán Quizapú de 1932 estudiados por otros autores, por lo que se asignan a dicho evento volcánico. Las tefras depositadas en la zona de estudio son de tamaño arena muy fina a mediana con significativa cantidad de fracciones menores a 10 µm. Las trizas son pumíceas, fibrosas, con diferentes conformaciones morfológicas y abundante vesicularidad que favorece el entrampamiento de partículas menores en las vesículas de las mayores. La composición química revela un alto contenido de sílice que alcanza hasta cerca del 70% de los componentes, con alrededor de un 15% de Al y cantidades subordinadas de K, Na, Ca, Zn, Mg, Cu, Fe y Ti. Es notorio el alto contenido de K, asociado a un aumento relativo por desilicación de la tefra con el transcurso del tiempo. También son importantes los contenidos de Fe y Cu, en este último caso posiblemente asociado a transformaciones post-depositacionales por meteorización. La composición de las trizas señala una erupción de tipo pliniano magmática andesítico-dacítica con contenido hidromagmático, intensa fragmentación y aglutinación durante el enfriamiento. Las evidencias de campo demostraron que la erupción afectó severamente la región sepultando y quemando suelos, carbonizando vegetación y cegando sectores marginales de la laguna. Estudios de esta naturaleza aportan a una clasificación sistemática y comparativa de la peligrosidad volcánica, considerando que las tefras resultantes de la erupción del Quizapú contienen hasta un 10% de partículas PM 10 (tamaño <10 µm) que corresponden a los tamaños “respirables” y en consecuencia altamente nocivos para la salud. Desde el enfoque socioeconómico, estos estudios sirven de base para su aplicación a otros eventos eruptivos muy recientes ocurridos en Argentina (volcanes Hudson, Copahue, Chaitén, Llaima, Peteroa y Puyehue-Cordón Caulle), y permiten elaborar metodologías específicas para analizar la peligrosidad de futuros eventos volcánicos

Análisis de las curvas de escorrentías mediante el software Surfer 13

En este proyecto se muestran las ventajas de utilizar un software para la búsqueda de solución de problemas como la erosión de la tierra debido a escorrentías. El área de estudio es un globo de terreno en la zona residencial Sueños de Soná, Provincia de Veraguas, República de Panamá. Se realiza el procesamiento de datos de campo y el uso de una plataforma que responda a necesidades de la actualidad, donde es posible visualizarse en 3D el perfil de la superficie y el comportamiento del terreno para la toma de decisiones

Setae from the pine processionary moth (Thaumetopoea pityocampa) contain several relevant allergens

BACKGROUND: Pine processionary larvae produce urticating hairs (setae) that serve for protection against predators. Setae induce cutaneous reactions in animals and humans. The presence of toxic or allergic mechanisms is a matter of debate. OBJECTIVES: To detect the presence of allergens in setae and to characterize them. MATERIALS AND METHODS: Setae extracts were characterized by gel staining and immunoblot, with sera from patients with immediate reactions and positive prick test reactions, as well as a rabbit antiserum raised against setae. Setae proteins were fractionated by high-performance liquid chromatography. The most relevant allergen was analysed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS), and its sequence was deduced from an expressed sequence tag bank. Results. Setae contained at least seven different allergens. The most intense detection corresponded to a protein of MW ~ 14,000 that was similar to thaumetopoein, a previously described protein with mast cell-degranulating properties. MALDI-MS-based de novo sequencing provided a partial amino acid sequence different from that of the previously described allergen Tha p 1, and it was named Tha p 2. This allergen was detected in 61% of patients, and it is therefore a new major caterpillar allergen. CONCLUSIONS: Penetration of the setae from the pine processionary caterpillar delivers their allergenic content in addition to causing mechanical or toxic injury.This work was supported by URTICLIM, a French project funded by the ‘Agence Nationale de la Recherche’ (ANR 07BDIV 013). Ana I. Rodriguez-Mahillo is a beneficiary of contract CA07/00046 from the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovacion, Spain.S

Targeting ribosomal G-quadruplexes with naphthalene-diimides as RNA polymerase I inhibitors for colorectal cancer treatment

Guanine quadruplexes (G4s) are non-canonical nucleic acid structures commonly found in regulatory genomic regions. G4 targeting has emerged as a therapeutic approach in cancer. We have screened naph thalene-diimides (NDIs), a class of G4 ligands, in a cellular model of colorectal cancer (CRC). Here, we identify the leading compound T5 with a potent and selective inhibition of cell growth by high-affinity binding to G4s in ribosomal DNA, impairing RNA polymerase I (Pol I) elongation. Consequently, T5 induces a rapid inhibition of Pol I transcription, nucleolus disruption, proteasome-dependent Pol I catalytic subunit A degradation and autophagy. Moreover, we attribute the higher selectivity of carbohydrate-conjugated T5 for tumoral cells to its preferential uptake through the overexpressed glucose transporter 1. Finally, we succinctly demon strate that T5 could be explored as a therapeutic agent in a patient cohort with CRC. Therefore, we report a mode of action for these NDIs involving ribosomal G4 targeting

Diet and lifestyle changes during the COVID-19 pandemic in Ibero-American countries: Argentina, Brazil, Mexico, Peru, and Spain

This study aimed to evaluate changes in dietary and lifestyle habits during the period of confinement due to the first wave of the COVID-19 pandemic in Ibero-American countries. A cross-sectional investigation was conducted with 6,325 participants of both genders (68% women), over 18 years of age and from five countries: Brazil (N = 2,171), Argentina (N = 1,111), Peru (N = 1,174), Mexico (N = 686), and Spain (N = 1,183). Data were collected during the year 2020, between April 01 and June 30 in Spain and between July 13 and September 26, in the other countries studied using a self-administered online survey designed for the assessment of sociodemographic, employment, physical activity, health status, and dietary habits changes. Most participants (61.6%), mainly those from Spain, remained constant, without improving or worsening their pattern of food consumption. Among those who changed, a pattern of better eating choices prevailed (22.7%) in comparison with those who changed toward less healthy choices (15.7%). Argentina and Brazil showed the highest proportion of changes toward a healthier pattern of food consumption. Peruvians and Mexicans were less likely to make healthy changes in food consumption (OR: 0.51; 95% CI: 0.4–0.6 and OR: 0.69; 95% CI: 0.4–0.8, respectively), when compared to Argentinians. Most respondents did not change their pattern of meal consumption, but those who did reduced their consumption of main meals and increased intake of small meals and snacks. Although most participants affirmed to be doing physical activity at home, about one-half reported perception of weight gain. Individuals with alterations in sleep pattern (either by increasing or decreasing sleep time) were more likely to change their diets to a healthier pattern. In contrast, individuals with confirmed diagnosis of COVID-19 and those who reported feeling anxious were more likely to perform changes to a less healthy eating pattern (OR: 1.72; 95% CI: 1.2–2.3 and OR: 1.21; 95% CI: 1.1–1.4, respectively). In conclusion, although most participants remained constant in their eating habits, lifestyle changes and anxiety feelings were reported. Among those who changed patterns of food consumption, healthier choices prevailed, with differences between countries. However, there were alterations in the distribution of meals, with higher consumption of snacks and small meals. These results can be used to guide policies to prevent deleterious consequences that may affect the incidence of chronic diseasesWe acknowledge the National Council for Scientific and Technological Development (CNPq) which provided MCBM a productivity fellowship and the Coordination for the Improvement of Higher Education Personnel (CAPES) which granted OE-M a Ph.D. scholarship. The project developed in Spain was supported by the Program of R&D activities between research groups of the Community of Madrid in Social Sciences and Humanities, co-financed with the European Social Fund (H2019/HUM-5802

Living with chronic illness scale: international validation of a new self-report measure in Parkinson’s disease

Understanding how a person lives with a chronic illness, such as Parkinson’s disease (PD), is necessary to provide individualized care and professionals role in person-centered care at clinical and community levels is paramount. The present study was aimed to analyze the psychometric properties of the Living with Chronic Illness-PD Scale (EC-PC) in a wide Spanish-speaking population with PD. International cross-sectional study with retest was carried out with 324 patients from four Latin American countries and Spain. Feasibility, acceptability, scaling assumptions, reliability, precision, and construct validity were tested. The study included 324 patients, with age (mean±s.d.) 66.67±10.68 years. None of the EC-PC items had missing values and all acceptability parameters fulfilled the standard criteria. Around two-third of the items (61.54%) met scaling assumptions standards. Concerning internal consistency, Cronbach’s alpha values were 0.68–0.88; item-total correlation was &gt;0.30, except for two items; item homogeneity index was &gt;0.30, and inter-item correlation values 0.14–0.76. Intraclass correlation coefficient for EC-PC stability was 0.76 and standard error of measurement (s.e.m.) for precision was 8.60 (for a EC-PC s.d.=18.57). EC-PC presented strong correlation with social support (rS=0.61) and moderate correlation with life satisfaction (rS=0.46). Weak and negligible correlations were found with the other scales. Internal validity correlations ranged from 0.46 to 0.78. EC-PC total scores were significantly different for each severity level based on Hoehn and Yahr and Clinical Impression of Severity Index, but not for Patient Global Impression of Severity. The EC-PC has satisfactory acceptability, reliability, precision, and validity to evaluate living with PD